This invention relates to a lawn moving machine, and, more particularly, it is concerned with a power transmission device for the lawn mowing machine, in which the grass cutting blade is driven by an internal combustion engine or an electric motor.
In this type of the lawn mowing machine, most of injuries caused to operators during its use is due to the cutting blade in rotation. For the safety measures against such possible danger of injury, there have so far been developed various devices such that a switch is provided at a position of the handle grip so that it may be closed simultaneously with gripping of the handle, and the prime mover continues to be operated so far as the handle is kept gripped, and when the operator leaves his hands off the handle, the prime mover is stopped.
In the abovementioned safety device, however, when it is necessary for the operator to leave his hands off the handle very often, the lawn mowing machine operated by the internal combustion engine should be re-started at every time the engine is stopped, and, at the same time, such starting operation should be effected at the gripping position of the handle with the consequence that the engine starting device become complicated. In the case of the lawn mowing machine operated by the electric motor, frequent start and stop of the electric motor impair the durability of the electric motor.